Surface covering connection joints

ABSTRACT

The present technology relates to connection joints for surface coverings which includes but is not limited to floor coverings and building panels. Embodiments of the present technology include connection joints that are strong and allow for the use of less material than is needed for tongue and groove connection joints. The connection joints includes cleats, clefts, and/or gap shims which allow for swelling and shrinking of the floor covering while maintaining a strong connection and preventing damage to the floor covering.

BACKGROUND OF THE INVENTION

Field of the Invention

The technology of the present application generally relates to a system for providing a connecting joint along adjacent joint edges of two building panels. More particularity, the technology provides new and improved connection joints that provide strength and use less material than existing connection joints. Thus, this technology is especially well suited for use in joining thin floor covering panels.

Description of Related Art

The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also correspond to implementations of the claimed technology. The term “plank” is used in a functional sense indicating a generally elongated structural member.

A common type of surface covering is wood flooring. Wood flooring may consist of a plurality of adjacent wooden floor planks affixed to a sub-floor. FIG. 1A shows a cross-section of a wooden floor plank 100, the floor plank may be comprised of a top side 102, a bottom side 104, two edges 106, 108 along the longitudinal sides of the plank, and two ends. The cross-section shown is perpendicular to the two edges and includes a tongue and grove connection joint. The tongue 110 is positioned on a portion of a first edge 106 of a floor plank and the groove 112 is positioned on a second edge 108 of the floor plank. A method of installing floor planks with tongue and groove connection joints includes affixing the tongue side of a first floor plank to a sub-floor 114 with a fastener 116, for example a nail, and positioning the groove side of a second floor plank to receive a portion of the tongue of the first floor plank as is shown in FIG. 1B. In the examples the sub-floor 114 and fastener 116 are shown for illustrative purposes and in practice the sub-floor may be thicker relative to the floor plank 100 than is shown. Further, the fastener may be relatively longer than shown, for example three fifths of the total length of the fastener may be in the sub-floor with two fifths of the length extending through the floor plank. In this method the groove side of the second floor plank is not fastened directly to the sub-floor and is prevented from moving in a vertical direction away from the sub-floor by the tongue of the first floor plank. To create an area of floor covering, this step is repeated with each tongue side of the previously installed floor plank and a groove side of a newly installed floor plank.

Floor planks with tongue and groove connection joints require substantial thickness in order to form a strong joint and a large portion of each floor plank remains as residual waste when the floor plank is replaced. The top portion of the cross-sections of the floor planks in FIG. 1B comprises a wear layer 118 located between the top surface 102 and a bottom portion 120 of the planks. When floor covering is damaged, for example through normal wear and tear, the floor covering is resurfaced using a device such as a sander. Each time the resurfacing process removes about one millimeter of wood material from the top surface of the wear layer 118 creating a new smooth top surface, the overall thicknesses of the wear layer and the plank are reduced. After refinishing the planks several times the wear layer is exhausted leaving only the bottom portion 120 of the planks and an exposed head of the fastener 116, as shown in FIG. 1C. At this point the floor covering needs to be replaced because it can no longer be refinished because no wear layer remains to be resurfaced and further the exposed head of the fastener may damage a resurfacing device. As is shown is FIG. 1C about two thirds of the original plank remains after the wear layer is exhausted and therefore a large portion of the wood of the original floor plank is thrown away. It is therefore desirable to provide surface coverings that use less material to make and have less residual waste.

To manufacture a thin floor plank with a tongue and groove connection joint either, one or more of the tongue, bottom portion of the groove, or top portion of the groove must be made thinner in order to reduce the overall thickness of the floor plank. It is more beneficial to reduce the thickness of the tongue and/or bottom portion of the groove to reduce overall plank thickness because reducing the top portion of the groove will reduce the thickness of the wear layer of the floor plank and therefore reduce the life span of the floor plank. Reducing the thickness of the tongue and/or bottom portion of the groove results in a connection joint that is not a mechanically strong joint because one or more of the tongue, or bottom portion of the groove will be too thin and will become flimsy and likely to crack or break if the joint is stressed. Therefore it is desirable to provide a connection joint that allows overall thickness of the board to be reduced while maintaining a large proportion of wear layer and maintaining a mechanically strong connection joint.

Surface coverings tend to be exposed to changes in temperature and humidity which may affect characteristics of the coverings. For example, wooden surface coverings in a high humidity climate may start to swell and cause cupping or even buckling problems. In a low humidity dry climate wooden floor planks may shrink. Shrinking may cause lateral movements perpendicular to the direction of the grain. Under this condition, in a nail-down application example the un-affixed side of a first plank may move away from an affixed side of a second plank, which results in a lateral separation between the planks. This lateral separation may cause loosening of an un-affixed side of a plank causing a hazard or damage to the floor covering. It is therefore desirable to provide a surface covering with a connection joint that reduces buckling and loosening caused by swelling and shrinking conditions.

SUMMARY OF THE INVENTION

The present technology relates to connection joints for surface coverings which includes but is not limited to floor coverings and building panels. Embodiments of the present technology include connection joints that are strong and allow for the use of less material than is needed for tongue and groove connection joints. In embodiments related to floor coverings, these advantages are accomplished by reducing total thickness of a floor plank while increasing the thickness of the wear layer relative to the overall thickness of the floor plank and still be able to maintain a structurally strong connection joint.

In embodiments the wear layer comprises a larger portion of the thickness of a plank than planks with tongue and groove connection joints. For example 30%-70% compared to ˜30% with tongue and groove. In embodiments the same thickness of wear layer may be provided with a thinner overall plank thickness. A thinner overall plank thickness significantly improves the log yield, the amount of area, e.g. square footage, of surface coverings that a single log can produce. Therefore embodiments of the technology may save thousands of trees per year. Further, because less volume of raw material is needed to produce the same square footage of surface covering products, manufacturing costs will be reduced, as well as transportation costs and drying process costs, which may allow manufacturers to be more competitive by offering consumers superior products at a lower costs than competitors, which is beneficial to both manufacturers and consumers.

The higher percentage of wear layer may also reduce the amount of residual waste because the amount of material left after the floor plank can no longer be refinished is significantly less. The higher percentage of wear layer may also be implemented to increase the lifetime of the plank by increasing the thickness of the wear layer without increasing the overall thickness of the plank.

These increases in wear layer thickness are accomplished with improved connection joints. Embodiments of connection joints provide equal or greater structural strength than existing connection joints, such as tongue and groove, while using less material. This advantage is achieved by using unique shapes that will be described in detail below. Embodiments further provide connection joints that maintain strength and surface evenness when conditions cause expansion (e.g. swelling) and contraction (e.g. shrinking) of the panels. This is achieved through unique shapes of connection joints which include gaps, swell reliefs, and one or more overlapping surfaces that will be described below.

Other aspects and advantages of the present invention can be seen on review of the drawings, the detailed description and the claims, which follow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows a cross-section of a floor plank with a tongue and groove connection joints.

FIG. 1B shows a cross-section of two floor planks with tongue and groove connection joints affixed to a sub-floor prior to refinishing.

FIG. 1C shows a cross-section of two floor planks with tongue and groove connection joints affixed to a sub-floor after refinishing several times and needing to be replaced and thrown away.

FIG. 2A shows a perspective view of a floor plank including embodiments of connection joints.

FIG. 2B shows a top view the floor plank shown in FIG. 2A.

FIG. 3A shows the 3A-3A cross-section of the floor plank of FIG. 2B including edges with an embodiment of a connection joint.

FIG. 3B shows the 3B-3B cross-section of the floor plank of FIG. 2B including edges with an embodiment of a connection joint.

FIG. 3C shows a detailed portion of the slot of FIG. 3B.

FIG. 3D shows a detailed portion of the wedge of FIG. 3B.

FIG. 4A shows a cross-section of two adjacent floor planks including a wedge and wedge shaped slot connection joint.

FIG. 4B shows a cross-section of two adjacent floor planks including a wedge and wedge shaped slot connection joint further including a cleat and a cleft.

FIG. 5A shows a cross-section of two adjacent floor planks including edges with embodiments of a connection joint separated due to contraction of one or more planks.

FIG. 5B shows a cross-section of two adjacent floor planks including edges with embodiments of a connection joint separated with the un-affixed edge displaced in the vertical direction.

FIG. 5C shows a cross-section of two adjacent floor planks including edges with the embodiments of the connection joint shown in FIG. 4B separated due to contraction of one or more planks.

FIG. 5D shows a cross-section of two adjacent floor planks including edges with the embodiments of the connection joint with the un-affixed edge prevented from substantial vertical displacement due to the cleat and cleft.

FIGS. 6A-L shows cross-sections of floor planks including edges with different embodiments of connection joints.

FIGS. 7A and 7B show cross-sections of two adjacent floor planks including edges with embodiments of a connection joint during an installation process.

FIGS. 8A and 8B show cross-sections of floor planks including edges with embodiments of connection joints.

FIGS. 9A-9N show cross-sections of floor planks including edges with embodiments of connection joints which include gaps between contact sides when installed.

DETAILED DESCRIPTION

The following description of the technology will typically be with reference to specific structural embodiments and methods. It is to be understood that there is no intention to limit the invention to the specifically disclosed embodiments and methods but that the invention may be practiced using other features, elements, methods and embodiments. Embodiments are described to illustrate the present technology, not to limit the scope of the invention, which is defined by the claims. Those of ordinary skill in the art will recognize a variety of equivalent variations on the description that follows. Like elements in various embodiments are commonly referred to with like reference numerals.

FIG. 2A shows a view of a floor plank 100. A plurality of floor planks may be used as a floor covering over an area of a sub-floor. The floor plank shown includes two embodiments of connection joints, a wedge and a wedge shaped slot connection joint on the ends 200, 202 and a wedge with a cleat and a wedge shaped slot with a cleft connection joint along the edges 204, 206 of the plank 100. FIG. 2B shows a top view of the floor plank 100 in FIG. 2A including two labeled cross-sections, 3A-3A and 3B-3B.

FIG. 3A shows cross-section 3A-3A, omitting the central portion of the plank, including an embodiment of a wedge and slot connection joint. The embodiment of the connection joint in FIG. 3A includes a first side including a wedge 300 and a second side including a wedge shaped slot 302. FIG. 3B shows cross-section 3B-3B, including an embodiment of a connection joint. The embodiment of the connection joint in FIG. 3B includes a first side including a wedge 300 and a cleat 304 and a second side including a wedge shaped slot 302 and a cleft 306.

The embodiments in FIGS. 3A and 3B include an upper portion 315 of the plank 100 including two contact sides 312, 314, one on the wedge 300 side and one on the wedge shaped slot 302 side. The upper portion 315 of the plank 100 corresponds to the wear layer of the plank. In embodiments, the wear layer comprises around 30%-70% of the total thickness of the plank, for example for an overall plank thickness of 13 mm the wear layer may be 6 mm. In the example shown the wear layer is about 50% of the total thickness of the plank. The contact side 312 on the wedge side of a first plank is configured to abut against a contact side 314 on slot side of a second plank installed adjacent to the first plank, as shown in FIGS. 4A 4B. The embodiments shown include contact sides that are generally perpendicular to the top side of the plank and therefore generally vertical when installed as flooring, however in embodiments the contact sides may be of different shapes and positioned at various angles relative to the top side.

The wedge 300 shown in the embodiments in FIGS. 3A and 3B includes a upwardly facing side 310 on a top side of the wedge extending away from a first terminal position 317 of the contact side 312 toward a protruding tip 308, and an outwardly angled side 316 extending at an obtuse angle from the bottom side 104 of the plank toward the protruding tip 308. In embodiments the protruding tip 308 may be rounded, as shown in FIG. 3B, which creates a smooth guide to prevent the tip from catching on a portion of an adjacent plank during installation. Further, a corner 319 between the bottom side 104 of the plank and the outwardly angled side 316 may be rounded or chamfered.

In the embodiments the wedge 300 may include a protrusion on the outwardly angled side 316. FIG. 3B shows the wedge 300 including a protrusion in the form of a cleat 304 located proximate to a middle portion of the outwardly angled side 316. In this embodiment the cleat 304 is generally triangular in shape and includes two sides, a vertical cleat side 318 and a horizontal cleat side 320, as shown in FIG. 3D. In embodiments the sides of the cleat may be straight, angled or curved, and additionally in embodiments the cleat may have any number of one or more sides, for example a single curved side forming a generally semi-circular cleat as shown in FIG. 6E. In embodiments a recess 332 may be formed at the first terminal position 317 to provide a space to accommodate the head of a fastener, for example a nail, as shown in FIG. 3D.

The wedge shaped slot 302 shown in the embodiments in FIGS. 3A and 3B includes a horizontal downward facing side 322 and an inwardly angled side 324. The wedge shaped slot 302 is configured to be received by a wedge 300 of an adjacent plank and is sized and shaped to be substantially complementary to a wedge 300. The inwardly angled side 324 extends at an acute angle from the bottom side 104 of the plank toward the top side 102 and terminates at the horizontal downward facing side 322. The horizontal downward facing side 322 extends from a second terminal position 323 of the slot side contact side 314 to the end of the inwardly angled side 324 at position 321. Embodiments of connection joints may include a swell relief 326 located at an end portion 325 of the inwardly angled side 324 and adjacent to the bottom side 104. The swell relief 326 provides a relief expansion space to allow a floor plank to swell and expand, for example in a high moisture environment.

In the embodiment shown in FIG. 3B the slot 302 includes a cleft 306 located on a middle portion of the inwardly angled side 324, dividing the inwardly angled side into multiple portions. The cleft 306 is generally triangular in shape and includes two sides, a vertical cleft side 328 and a horizontal cleft side 330, as shown in FIG. 3C. The shape, size and location of the cleft is configured to be complementary to a cleat 304 of a plank installed adjacent to the plank with the slot 302 and cleft 306 as shown in FIG. 4B.

In embodiments, the angles between the plurality of sides of the wedge, cleat, cleft, and slot different than what is shown in FIGS. 3A and 3B. Angle A (θ_(A)) shown in FIG. 3D is located between the contact side 312 and the upwardly facing side 310 and may range from 30° to 150°, such as 90°, as shown in FIG. 3D. Angle B (θ_(B)) shown in FIG. 3D is located between the upwardly facing side 310 and the inwardly angled side 316 and may range from 10° to 80°, such as 45°, as shown in FIG. 3D. Angle C (θ_(C)) shown in FIG. 3D is located between the vertical cleat side 318 and the horizontal cleat side 320 and may range from 10° to 170°, such as 90°, as shown in FIG. 3D. Angle D (θ_(D)) shown in FIG. 3C is located between inwardly angled side 324 and the downward facing side 322. Since the slot 302 is configured to be received by the wedge 300, angle D can be identical or substantially identical, within a few degrees, to angle B of the wedge. Angle D can therefore range from 10° to 80°, such as 45°, as shown in FIG. 3C. Angle E (θ_(E)) shown in FIG. 3C is located between the vertical cleft side 328 and the horizontal cleft side 330. Since the cleft 306 is configured to be complementary to the cleat 304, angle E can be identical or substantially identical, within a few degrees, to angle C. It can range from 10° to 170°, such as 90°, as shown in FIG. 3C. Angle F (θ_(F)) shown in FIG. 3D is located between the bottom side 104 and the outwardly angled side 316 is an obtuse angle between 90° and 180°, such as 135°, as shown in FIG. 3D. Angle G (θ_(G)) shown in FIG. 3C is an acute angle located between the bottom side 104 and the inwardly angled side 324. Since the slot 302 is configured to be complementary to the wedge 300, angle G can be identical or substantially identical, within a few degrees, to the complementary angle of angle F. It can range between 0° and 90°, such as 45°, as shown in FIG. 3C.

The wedge 300 shown in the embodiments in FIGS. 3A and 3B is configured to act as a guide to receive a complementary wedge shaped slot 302 of an adjacent floor plank that is installed next to the floor plank with the wedge 300. In embodiments, when a first plank is installed adjacent to a second plank the contact side 312 of the first plank is in contact with the contact side 314 of the second plank, however one or more sides of the wedge 300 of a first plank may be separated by a small gap from one or more complementary sides of the slot 302 of the adjacent second plank. The embodiments in FIGS. 4A and 4B show a gap between all sides of the wedge of a first plank and the slot of a second plank. The relative size of the gap shown in FIGS. 4A and 4B is for illustrative purposes and in practice the gaps may be larger or smaller relative to the dimensions of the cross-section of the planks and further may vary in size between different sets of complementary sides of the wedge and slot.

In embodiments, in order to form a gap between complementary sides of the wedge and slot the dimensions of other sides need to be set accordingly. For example, to create a vertical gap between the upwardly facing side 310 of the wedge of a first plank and the downward facing side 322 of the slot of a second plank the contact side 314 of the second plank is made shorter than the contact side 312 of the first plank as is shown in FIGS. 4A and 4B. This gap between these two horizontal sides prevents the sides from hitting or rubbing each other during the process of installation and further provides minor adjustment space for better surface alignment. The other sides of the wedge and slot may be configured to form similar gaps with similar benefits.

FIG. 5A-D shows examples of separation of different embodiments of connection joints as a result of shrinking of the planks. In the examples shown a separation is formed between an affixed wedge side of a first plank and an un-affixed slot side of a second plank. The amount of separation, in addition to pre-existing gaps, between complementary sides is dependent on the angle of the sides relative to the direction of separation. With shrinking in the horizontal direction, the horizontal separation of the completely vertical sides is the greatest and the separation between angled sides decreases with an increasing horizontal component of the angle of the sides. Where the complementary sides are completely horizontal only little separation occurs during horizontal shrinking.

A gap between inward angled side 324 and the outward angled side 316 is formed when the horizontal separation occurs as shown in FIG. 5A, the inwardly angled side 324 of the un-affixed slot side of the second plank is no longer securely held against the sub-floor by outwardly angled side 316 of the affixed wedge side of the first plank. If the slot side of the second plank is forced in an upward direction for example in a case where the planks are on an uneven sub-floor and a person steps on the wedge side of the second plank causing the slot side to rise, the slot side of the second plank will move in a vertical direction until the end portion 325 of the inwardly angled side 324 contacts the outwardly angled side 316 of the wedge of the first plank. The amount of vertical movement generally corresponds to the vertical separation between the inwardly angled side 324 of the slot of the second plank and the outwardly angled side 316 of the wedge 300 of the first plank, as shown in FIG. 5B. For a given horizontal separation the vertical separation is dependent on angles B and D. Smaller angles B and D correspond to smaller vertical separation for a given horizontal separation. Therefore, embodiments with smaller angles B and D will allow less vertical movement for a given horizontal separation than embodiments with larger angles B and D.

In the embodiment shown in FIGS. 5C and 5D the upward movement of the second plank is additionally prevented by the horizontal cleat side 320 of the cleat 304 of the wedge 300 of the first plank and the horizontal side 330 of the cleft 306 of the slot 302 of the second plank. When an overlap of the horizontal cleat side 320 and horizontal cleft sides 330 exists the vertical movement of the second plank is limited by the amount of separation of these sides. As discussed above, since these are horizontal sides the vertical separation between these sides is not dependent on the horizontal separation caused by shrinking and therefore the vertical separation between these sides is equal to the vertical gap present between the two sides prior to separation of the planks caused by shrinking. It is beneficial to have horizontal cleat and cleft sides with sufficient lengths to maintain overlap at maximum shrinking of the planks to prevent vertical movement of the second plank. In an example embodiment, the floor plank may be 13 mm thick, with an 6 mm wear layer, a 7 mm bottom portion including the wedge and slot, and a horizontal cleat and cleft side each be about 1 mm. While in the embodiments shown the horizontal cleat and clefts sides are horizontal, in embodiments they may also be angled or have curved sides, or a combination of straight, angled or curved sides, and will still add similar benefits to the connection joint.

The surface coverings including embodiments of the connections joints may be installed in various ways. For example, floor planks can be installed using a fastener method as disclosed above, a glue-down method or a floating method. In a glue down method the planks may be glued down directly onto a subfloor, or the planks may be edge glued resulting in a glue-connected floating floor.

A method of installing floor planks 100 using a fastener method may include; nailing down a first row of planks along a guideline or straight wall with the wedge side facing the direction the floor covering is going to cover. Then either by face-nailing or nailing through the recess 332 of the wedge, fastening the first row of floor planks to a sub-floor 114. Then sliding 702 the slot side of a plank in the second row of planks horizontally along the sub-floor 114 toward the wedge side of the first row of floor planks, as shown in FIG. 7A. The protruding tip 308 of the wedge 300 of a first row plank 100 may guide the slots 302 of a second row plank as the second row plank slides into place. The second row plank is in place when the slot 302 of the second row plank is received by the wedge 300 of the first row plank and the contact side 312 of a first plank abuts the contact side 314 of the second plank, and the upwardly facing side 310 with the outwardly angled side 316 and the downward facing side 322 with the inwardly angled side 324 are also fully engaged. In embodiments the vertical cleat side 318 and the horizontal cleat side 320 of cleat 304 and the vertical cleft side 328 and the horizontal cleft side 330 of cleft 306 are also fully engaged, as is shown in FIG. 7B. During this horizontal sliding motion of the second row plank 100, the top side 102 of the second row plank is substantially on the same plane as the top side 102 of the first row plank 100. Once mated and before the second row plank 100 is affixed to the sub-floor 114 the plank is free to move in the horizontal direction away from the first row as the connection joint provides no resistance to movement in this direction. The second row plank 100 is then affixed to the sub-floor 114, in this example with a fastener 116. This process is repeated for each floor plank of additional rows.

Surface covering including embodiments of connection joints may be manufactured in a plurality of ways. For example, surface coverings may be manufactured from wooden planks from sawmills. Drying, planing and sanding processes may be performed to the wooden planks prior to performing cutting processes with various milling tools to form the features of the connection joints. For example, wooden floor planks with embodiments of connection joints may be manufactured using one or more milling processes to form wedges, slots, cleat, cleft, recesses, kerfs, bevels and swell reliefs. As shown in the embodiment in FIGS. 3A and 3B, the front joining plane 312 and the wedge 300 with the upwardly facing surface 310 and the bevel plane 316, may be formed along the entire length of one longitudinal side of the plank 100. The cleat 304 may be formed in the middle of the bevel plane 316. The rear joining plane 314 and the slot 302 with the downward surface 322 and the inclined plane 324 may be formed along the entire length of the opposite longitudinal side of the plank 100. The cleft 306 may be formed in the middle of the inclined plane 324. The swell relief 326 may be formed along the entire length of the bottom side of the plank 100.

FIG. 6A is a cross section view of a plank 100 with an embodiment of a connection joint according the present technology. The embodiment includes a triangular shape wedge and slot profile.

FIG. 6B is a cross section view of a plank 100 with an embodiment of a connection joint according the present technology. The embodiment includes a double triangular shape wedge and slot profile.

FIG. 6C is a cross section view of a plank 100 with an embodiment of a connection joint according the present technology. The embodiment includes a wedge and wedge shaped slot similar to embodiments disclosed above wherein the wedge includes a cleft and the wedge shaped slot includes a cleat.

FIG. 6D is a cross section view of a plank 100 with an embodiment of a connection joint according the present technology. The embodiment includes tilted contact sides. The angle of the tilted contact sides can range from 10° to 170°.

FIG. 6E is a cross section view of a plank 100 with an embodiment of a connection joint according the present technology. The embodiment including a wedge and wedge shaped slot similar to embodiments disclosed further including a cleat on the wedge and a cleft in the wedge shaped slot formed in a half circle shape profile. In embodiments the cleat and cleft can be in various shapes. Further the cleft may be of a first shape and the cleat a second shape wherein the cleft is configured to receive the differently shaped cleat and have similar functions as the cleat and cleft disclosed above.

FIG. 6F is a cross section view of a plank 100 with an embodiment of a connection joint according the present technology. The connection joint including a half circular shape profile for a wedge and slot.

FIG. 6G is a cross section view of a plank 100 with an embodiment of a connection joint according the present technology. The connection joint including a double half circular shape wedge and slot.

FIGS. 6H, 6I and 6J are cross sectional views of planks 100 with embodiments of connection joints according the present technology. The connection joints may be formed on multi-layer planks. The cross-section includes atop section and a bottom section made of the same or different material. Each portion may be construction of one or more layers. For example, the embodiment of FIG. 6H may include a solid wooden top portion and a vertically laminated wooden bottom portion, the embodiment of FIG. 6I may include a solid wooden top portion and a plywood bottom portion, and the embodiment of FIG. 6J may include a solid wooden top portion and a composite bottom portion. Embodiments with multiple portions provide the benefit of a strong top surface that is able to be refinished multiple times and a less expensive bottom portion that may also be more environmentally friendly by using non-wood materials.

FIG. 6K is a cross section view of a plank 100 with an embodiment of a connection joint according the present technology. The connection joint including an inverted shape wedge and slot profile.

FIG. 6L is a cross section view of a plank 100 with an embodiment of a connection joint according the present technology. The connection joint including a slanted inverted shape wedge and slot profile.

FIGS. 8A and 8B show cross sections of embodiments including a cleat 304 positioned at the upper end of the outwardly angled side 316. In embodiments, positioning the cleat at the upper end of the outwardly angled side is beneficial because it allows for smaller wedges, which results in less wood used to create a plank while still maintaining the strength and performance benefits of the joint. For example, the horizontal distance between the contact side 312 and protruding tip 308 may be 4 mm.

As shown in FIG. 8A, and as disclosed above, contact side 312 may form an obtuse angle with the top side 102. An obtuse angle between contact side 312 and top side 102 results in a non-vertical seam when the plank is used to create a horizontal floor covering. Further, as shown in FIG. 8A, and as disclosed above, upwardly facing side 310 may form an obtuse angle with contact side 312 and upwardly facing side 310 may be downwardly sloping in a direction away from the plank and in a direction toward the bottom side 104.

The wedge shaped slot 302 of FIG. 8A is configured to be received by the wedge 300 of FIG. 8A. As shown in FIG. 8A, wedge shaped slot 302 includes a horizontal downward facing side 322 and a vertical cleft side 328. When two planks as shown in FIG. 8A are installed next to one another with the horizontal cleat side 320 overlapping the horizontal cleft size 330, as discussed above, a void is formed and defined by portions of upwardly facing side 310, vertical cleft side 328, and horizontal downward facing side 322.

As noted above, protruding tip 308 may be rounded, and one or more sides of a cleat, and corresponding cleft, may be curved. As shown in FIG. 8B, the cleat 304 is positioned at the upper end of the outwardly angled side 316 and includes a horizontal cleat side 320 and a curved side 350 extending up from the horizontal cleat side 320 and forming a rounded protruding tip 308 of the cleat 304.

The wedge shaped slot 302 of FIG. 8B is configured to be received by the wedge 300 of FIG. 8B. As shown in FIG. 8B, the wedge shaped slot 302 is similar to the wedge shaped slot of FIG. 8A. In embodiments, wedge shaped slots may be complementary to a plurality of differently shaped wedges, and wedges may be complementary to a plurality of differently shaped wedge shaped slots. The wedge shaped slots 302 of FIG. 8B includes a horizontal downward facing side 322 and a vertical cleft side 328. When two planks as shown in FIG. 8B are installed next to one another with the horizontal cleat side 320 overlapping the horizontal cleft size 330, as discussed above, a void is formed and defined by portions of upwardly facing side 310, rounded protruding tip 308, vertical cleft side 328, and horizontal downward facing side 322.

Since wood is a hygroscopic material, as noted above, high humidity may cause wood floor coverings to swell. For example, a 5 inch wide plank of white oak may increase around 2.9% in moisture content when the indoor environment changes from 60 degrees Fahrenheit and 30% relative humidity to 80 degrees Fahrenheit and 50% relative humidity. This increase in moisture content may increase the width of the plank about 1.3 mm, using the dimensional change coefficient of 0.00365 for white oak. In more extreme changes in environment, such as flooded and under water, a plank may swell even more.

Swelling of planks may result in cupping or buckling of a floor covering. Specifically, swelling of planks of a floor covering may cause the abutting contact sides to expand toward each other and therefore exert force against each other. This expansion and force causes portions of the floor covering along the seams where contact sides meet to become raised relative to the rest of the top side of the plank in order to accommodate the additional volume of the swollen planks. This is referred to as cupping. Also, swelling of a plurality of rows of planks may cause the planks to pull away from the sub-floor and form an arc to accommodate the additional width and length caused by the swelling of the plurality of planks, this is referred to as buckling. Cupping and buckling are undesirable because they may permanently damage the floor covering.

In embodiments cupping and buckling may be reduced, or eliminated, by providing a gap between installed planks. In embodiments the gap is provided between the contact sides of the planks. In embodiments, one or more edges of the joint may include features to contact the opposite edge of the joint to create the gap between the contact sides when installed. The gap between contact sides when the planks are installed and under typical indoor environmental conditions, for example at 70 degrees Fahrenheit and 40% relative humidity, may be between 0.1 mm to 2.0 mm, and more preferably between 0.3 and 0.5 mm. The size of the gap may be determined based on a combination of one or more of the width of the plank, the thickness of the plank, the species of wood of the plank, and the expected seasonal environmental changes where the plank is installed. The gap allows the planks to swell and each expand, roughly half the size of the gap in each direction, before the contact sides make contact and the edges start to compress each other which may result in cupping or buckling, as discussed above.

In embodiments, the wedge and wedge shaped slot may be sized and shaped to form the gap between contact sides. In embodiments, one or more sides of a wedge or a wedge shaped slot may include a gap shim configured to form the gap between contact sides. Gap shims may protrude away from one or more sides of a wedge or wedge shaped slot. Gap shims are configured to create a first gap between at least the side, of the wedge or wedge shaped slot, which the gap shim protrudes from and a corresponding complementary side of an adjacent plank which the gap shim contacts. The gap shim is further configured create the gap between the contact sides, as discussed above. In embodiments, gap shims may be substantially triangular in shape and end in a contact tip. However, in embodiments, gap shims may be other shapes, for example round or square, In embodiments, the end of a gap shim configured to contact an adjacent plank may form a point, may be rounded or may be flat. In embodiments, gap shims extend along the entire length or a portion of the length of an edge of a plank.

FIG. 9A shows a cross-section of a floor plank similar to the cross-section of the floor plank of FIG. 3B and including similar features. As shown in FIG. 9A, in embodiments, a gap shim 901 may be provide on the wedge 900 side of a plank. When two planks including the joint shown in FIG. 9A are installed, as shown in FIG. 9B, the gap shim 901 is configured to contact the end side 903 of wedge shaped slot 902. As shown, the end side 903 is continuous with the vertical cleft side 928. However in embodiments, cleft 906 may be located at an intermediate position on the inwardly angled side 924 with the vertical cleft side 928 at the intermediate position and the end side 903 extending upward from the top of the inwardly angled side 924. The gap shim 901 contacting the end side 903 creates a first gap between the end side 903 of the wedge shaped slot 902 and the end side 905 of the wedge 900. As shown, the end side 905 of the wedge 900 is continuous with the vertical cleat side 918. However in embodiments, cleat 904 may be located at an intermediate position on the outwardly angled side 916 with the vertical cleat side 918 located at the intermediate position and the end side 905 extending upward from the top of the outwardly angled side 916. The gap created by the gap shim further forms a gap between contact sides 912 and 914, which creates room for planks to swell before butting each other resulting in cupping or buckling, as discussed above.

FIGS. 9C-9G show additional embodiments including gaps shims 901. As shown, inwardly angled side 924 of wedge shaped slot 902 may include a gap shim 901 configured to contact an outwardly angled side 916 of a wedge 900. In embodiments, the gap shim 901 may be positioned along any point of inwardly angled side 924 of the wedge shaped slot 902. For example, as shown in FIGS. 9C and 9D, the gap shim 901 may be positioned in the middle of inwardly angled side 924. As shown in FIGS. 9E and 9F, the gap shim 901 may be positioned at the top of inwardly angled side 924. As shown in FIGS. 9G and 9H, the gap shim 901 may be positioned at the bottom of inwardly angled side 924. As shown in FIGS. 9B, 9D, and 9H, and discussed above, contact sides 912 and 914 may form non-right angles with the top sides of planks which results in non-vertical seams when installed as a horizontal floor covering. For example, as shown in FIGS. 9C and 9D, contact side 912, corresponding to the wedge side of the plank, may form an obtuse angle with the top side of the plank. Further, for example, as shown in FIGS. 9G and 9H, contact side 912, corresponding to the wedge side of the plank, may form an acute angle with the top side of the plank.

As shown in FIGS. 9A-9H, in embodiments, the horizontal distance between protruding tip 908 and terminal position 917 may be greater than the horizontal distance between the second terminal position 923 and the end side 903. This difference in horizontal distance corresponds to the size of the gap between contacts side 912 and 914. As shown, when installed, protruding tip 908 contacts end side 903.

During installation, as discussed above, the contact of a gap shim 901 and a corresponding side on an adjacent installed plank and/or the contact of the protruding tip 908 and end side 903 prevent the contact sides 912 and 914 from contacting and create the gap between the contact sides. FIGS. 9I and 9J show an embodiment including a gap between contact side 912 and 914 created by contact of protruding tip 908 and end side 903. As shown in FIGS. 9I and 9J, in embodiments, the gap between contact sides 912 and 914 is created by sizing features of complementary edges to create the gap, without the use of a gap shim on either edge of the joint. As shown in FIG. 9J, the contact sides 912 and 914 form right angles with the top side of the plank, and therefore result in a vertically oriented gap when the planks are installed as a horizontal floor covering. However, in embodiments including gaps, the gap may be oriented vertically, as shown in FIG. 9J, or at an angle relative to vertical, as shown in FIGS. 9D and 9H.

As shown in FIGS. 9K and 9L, in embodiments, the wedge shaped slot 902 may include the gap shim 901. As shown, gap shim 901 may extend from end side 903 and be configured to contact end side 905 of wedge 900, as shown in FIG. 9L.

As shown in FIGS. 9M and 9N, in embodiments, the wedge shaped slot 902 may include the gap shim 901 extending from downwardly angled end side 907 and be configured to contact an angled portion of upwardly facing side 910 of wedge 900, as shown in FIG. 9N.

In embodiments, gap shims may be located on any side of the wedge or wedge shaped slots. In embodiments, a joint may include one of more gap shim extending from one or more sides. For example, inwardly angled side may include two gap shims. Further for example, a side of a wedge may include a first gap shim, and a side of the wedge shaped slot may include a second gap shim.

Surface covering including embodiments of connection joints as discussed above may be manufactured in a plurality ways. For example, wooden floor planks with embodiments of connection joints many be manufactured using one or more milling process to form wedges, cones, slots, cleat, cleft, recesses, kerfs, bevels, gap shims and expansion reliefs.

While the present technology is disclosed by reference to the embodiments and examples detailed above, it is to be understood that these examples are intended in an illustrative rather than in a limiting sense. For example, while the present technology is particularly advantageous as use with floor coverings, embodiments of the connection joints may be used in other surface covering applications, including, but not limited to construction panels, such as housing indoor and outdoor frame panels, structural panels, subfloor panels, roofing panels, wall panels, ceiling panels, floor covering panels, decorative panels, decks and patio panels, furniture surfaces, shelving, partition panels, horizontal and vertical surfaces, table tops, counter tops, and other surface coverings or parts currently using tongue and groove connecting systems.

Further, while embodiments were disclosed in relation to a rectangular plank, such as the one shown in FIG. 2A, embodiments of the connection joints of the present technology may be used with various shaped panels including any combination of straight, angled or curves sides, for example panels in the shape of rectangles, squares, triangles, other polygons, arcs, circles and semi-circles. Further, the connection joints of the present technology may be used on adjacent panels that have different sizes, shapes and orientations, for example in parquet flooring. Further, the technology may be used with surface covering panels with top and bottom sides that are not flat, for example the tops and bottoms sides may be curved or include angles.

Further, embodiments of connection joints have been described using cross-sections including what may be referred to as a male side (e.g. wedge) and a female side (e.g. slot) of connection joints. In embodiments, a surface covering panel may include a single male or female of a connection joint. Further, a surface covering panel may include any combination of male and female sides of a plurality of connection joints. For example, the two edges of a four side floor plank may include complementary connection joints (e.g. male and female), identical connection joints (e.g. male and male), or different connection joints (e.g. male of first type of connection joint and female of second type of connection joint). Further one or more sides or edges of a panel may have no connection joints while other sides do include one or more connection joints.

Further, the embodiments of connection joints have been described using cross-sections to illustrate various functional aspects of different connection joints. The cross-sections may further include other functional or ornamental features of a plank. For example, the cross-section of a plank 100, may further include provides kerf cuts 334, along the bottom side 104, as shown in FIG. 3B. The kerf cuts may be formed along the entire length of the plank in the longitudinal direction for the purpose of dimensional stability. The kerf cuts can be formed by removing a predetermined amount of wood material from the lower portion of the plank with a milling process. The kerf cuts further provide a relief space to accommodate swell of floor plank when it is under high humidity environments. In addition, the kerfs also provide a space to accommodate excess glue in glue-down installations. Additionally ornamental features such as a bevel may be formed around the parameters of the top side 102 of a plank 100. The bevel improves the aesthetic appearance of installed wood floor planks by making any slight irregularities in thickness of floor planks less conspicuous.

The embodiments described and shown in the figures portray relative dimensions of cross sections of connection joints, however other embodiments may have different relative dimensions of the various components without departing from the scope of the technology.

Descriptions of embodiments of the present technology included wood as an example of a material that may be used to construct the connection joints. However, other materials and combinations of materials may alternatively be used including, metals, plastics, composites, bamboo, cork, fiberboard, coconut palm, particle board (e.g. MDF and HDF), and other natural, organic, recycled, or synthetic materials, or any other similar materials. Those in the art will understand that any suitable material, now known or hereafter developed, may be used in making the panels described herein. In embodiments including two or more layer engineered floors, the layers may be made from any combination of the conventional materials used in the surface covering product industry.

The various aspects, embodiments, implementations or features of the described embodiments can be used separately or in any combination. For example, any of the features disclosed in relation to the embodiments shown in FIGS. 3A-3B, 8A and 8B may be used in combination with any of the features disclosed in relation to the embodiments shown in FIGS. 9A-9N. It is contemplated that modifications and combinations will readily occur to those skilled in the art, which modifications and combinations will be within the spirit of the invention and the scope of the following claims. What is claimed is: 

1. A method of forming a floor covering comprising: affixing a first floor plank to a sub-floor, the first floor plank including a first edge including a first contact side, and a wedge shaped portion including a cleat; mating the first edge of the affixed first floor plank to a complementary shaped second edge of a second floor plank, the second edged including a second contact side and a wedge shaped slot including a cleft; affixing the second floor plank to the sub-floor with the first edge of the first floor plank mated with the second edge of the second floor plank; wherein the cleat and cleft are configured to maintain an overlap to limit vertical movement of the second floor plank when the second floor plank shrinks in a direction away from the first floor plank, due to a change in temperature or humidity, and increases a distance between the first edge and the second edge.
 2. The method of claim 1, wherein the first floor plank is affixed to the sub-floor with the first contact side of the first floor plank contacting the second contact side of the second floor plank.
 3. The method of claim 1, wherein the first floor plank is affixed to the sub-floor with the first contact side of the first floor plank and the second contact side of the second floor plank separated by a gap.
 4. The method of claim 3, wherein the gap is between 0.3 mm and 0.5 mm and is configured to reduce cupping or buckling of the floor covering due to swelling of the plank.
 5. The method of claim 3, wherein the wedge shaped portion of the first floor plank includes a gap shim extending from a side of the wedge shaped portion, wherein the second floor plank is affixed to the sub-floor with the gap shim contacting a side of the wedge shaped slot of the second floor plank, and wherein the gap shim prevents the first contact side of the first floor plank and the second contact side of the second floor plank from contacting during the mating of the first edge of the first floor plank to the second edge of the second floor plank.
 6. The method of claim 3, wherein the wedge shaped slot of the second floor plank includes a gap shim extending from a side of the wedge shaped slot, wherein the second floor plank is affixed to the sub-floor with the gap shim contacting a side of the wedge shaped portion of the first floor plank, and wherein the gap shim prevents the first contact side of the first floor plank and the second contact side of the second floor plank from contacting during the mating of the first edge of the first floor plank to the second edge of the second floor plank.
 7. A floor plank for horizontal flooring assemblies comprising: a top side; a bottom side substantially parallel to the top side, wherein the floor plank is affixed to a horizontal surface with the bottom side contacting the horizontal surface; a first edge extending from the top side to the bottom side comprising; a first contact side extending from the top side to a first terminal position between the top side and the bottom side; and a wedge shaped portion comprising; a first upwardly facing side extending from the first terminal position; a first angled side extending between the bottom side and the first upwardly facing side and forming an obtuse angle with the bottom side; and a cleat protruding from the first angled side; wherein the first edge is configured to mate with a second edge, of a second floor plank affixed to the horizontal surface adjacent the floor plank, the second edge having a complementary shape to the first edge; and wherein the second floor plank is configured to shrink in a direction away from the floor plank when affixed to the horizontal surface adjacent the floor plank, creating a gap between the first edge and the second edge and the cleat of the first edge and a cleft of the third edge are configured to maintain an overlap to limit vertical movement of the second floor plank when shrunk.
 8. The floor plank of claim 7, wherein the cleat includes a horizontal cleat side extending from and forming an obtuse angle with the first angled side.
 9. The floor plank of claim 8, wherein the first upwardly facing side extends downwardly from the first terminal position to the cleat.
 10. The floor plank of claim 9, wherein the cleat includes a vertical cleat side extending from an end of the first upwardly facing side to the horizontal cleat side.
 11. The floor plank of claim 8, wherein the end of the first upwardly facing side includes a rounded portion.
 12. A floor plank for horizontal flooring assemblies comprising: a top side; a bottom side substantially parallel to the top side, wherein the floor plank is configured to be affixed to a horizontal surface with the bottom side contacting the horizontal surface; a first edge extending from the top side to the bottom side comprising; a first contact side extending from the top side to a first terminal position between the top side and the bottom side; and a wedge shaped portion comprising; a first upwardly facing side extending from the first terminal position; and a first angled side extending between the bottom side and the first upwardly facing side and forming an obtuse angle with the bottom side; and a second edge extending from the top side to the bottom side and opposite the first edge, wherein the second edge comprises a second edge geometry having a complementary shape to the first edge; wherein the first edge is configured to mate with a third edge, of a second floor plank affixed to the horizontal surface adjacent the floor plank, the third edge comprising the second edge geometry, and wherein the first edge is configured to form a gap between the first contact side of the floor plank and a second contact side of the second floor plank.
 13. The method of claim 12, wherein the gap is between 0.3 mm and 0.5 mm and is configured to reduce cupping or buckling of the floor covering due to swelling of the plank.
 14. The floor plank of claim 12, wherein the wedge shaped protrusion further comprises a cleat protruding from the first angled side, and wherein the cleat is configured to contact a side of the third edge of the second floor plank in order to create the gap between the first contact side of the floor plank and the second contact side of the second floor plank.
 15. The floor plank of claim 12, wherein the second edge geometry includes a gap shim extending from a side of a wedge shaped slot complementary in shape to the wedge shaped portion, and wherein a side of the wedge shaped portion is configured to contact the gap shim of the second floor plank in order to form the gap.
 16. The floor plank of claim 15, wherein the second edge geometry includes an inwardly angled side, forming a bottom portion of the wedge shaped slot, and the gap shim extends out from the inwardly angled side.
 17. The floor plank of claim 15, wherein the wedge shaped portion includes a vertical end side configured to contact the gap shim of the second plank.
 18. A floor plank for horizontal flooring assemblies comprising: a top side; a bottom side substantially parallel to the top side, wherein the floor plank is configured to be affixed to a horizontal surface with the bottom side contacting the horizontal surface; a first edge extending from the top side to the bottom side comprising; a first contact side extending from the top side to a first terminal position between the top side and the bottom side; and a wedge shaped slot comprising; a first downwardly facing side extending from the first terminal position and facing toward the bottom side; a first angled side extending from the bottom side toward the first downwardly facing side and forming an obtuse angle with the bottom side; and a gap shim extending outwardly from a side of the wedge shaped slot; and wherein the first edge is configured to mate with a second edge of a second floor plank affixed to the horizontal surface adjacent the floor plank, the second edge having a complementary shape to the first edge, and wherein the gap shim is configured to contact a side of a wedge portion of the second edge to form a gap between the first contact side of the floor plank and a second contact side of the second floor plank.
 19. The floor plank of claim 18, wherein the gap shim extends from the first angled side.
 20. The floor plank of claim 18, wherein the first downwardly facing side includes a portion forming and acute angle with the top side, and wherein the gap shim extends downwardly from the portion. 